The 4 million customers of online and mobile brokerage Robinhood don’t receive the investment research or portfolio tools offered by more-established brokerages. And no, the brokerage’s app doesn’t let you steal from the rich to give to the poor. But Robinhood does offer no-commission and no-fee trades for all U.S.-listed stocks and ETFs. There’s also a free options trading service and, in some states, cryptocurrency trading. (Robinhood’s revenue comes from selling premium subscriptions that allow after-hours trading and margin trades.) There’s no minimum to invest. Just sign up, link your bank account and enjoy the savings.